Portable audio mixer



FIG. 1 is an isometric view of the design of the present application taken from above, with a computing device shown in broken line docked with the portable audio mixer;

FIG. 2 is a bottom isometric view of the design of FIG. 1;

FIG. 3 is a top view of the design of FIG. 1;

FIG. 4 is a bottom view of the design of FIG. 1;

FIG. 5 is an end view of the design of FIG. 1;

FIG. 6 is an end view of the design of FIG. 1 taken from the opposite end of the design; and,

FIG. 7 is a side view of the design of FIG. 1.

The elements depicted in broken lines in the figures are included for environmental purposes only, and form no part of the claimed design. 

CLAIM The ornamental design for a portable audio mixer, as shown and described. 